<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>hash test</title>
</head>
<body>
<p>hash test</p>
<button id="btn1">修改 hash</button>

<script>
// hash 变化，包括：
// a. JS 修改 url
// b. 手动修改 url 的 hash
// c. 浏览器前进、后退
window.onhashchange = (event) => {
  console.log('old url', event.oldURL)
  console.log('new url', event.newURL)

  console.log('hash:', location.hash)
}

// 页面初次加载，获取 hash
document.addEventListener('DOMContentLoaded', () => {
  console.log('hash:', location.hash)
})

// JS 修改 url
document.getElementById('btn1').addEventListener('click', () => {
  location.href = '#/user'
})
</script>
</body>
</html>
